I would be in favor of open models actively defaulting to watermarking by default if they could make unobtrusive. An opt out watermarking scheme honestly would handle most bad actors to me tbh.
Bad guys are normally not the brightest. Yes even big expensive bad actors.
Making it the norm also makes it a red flag if content has other markers but seems intentionally obfuscated.
Honestly I’ve been trying to figure out how to convince more people in my credit union why FOSS matters.